VersionedApplication.java

package com.sequenceiq.cloudbreak.shell;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

import org.springframework.core.io.ClassPathResource;

public class VersionedApplication {

    public static final String LONG_VERSION = "--version";

    public static final String SHORT_VERSION = "-v";

    private VersionedApplication() {

    }

    public boolean showVersionInfo(String[] args) {
        if (checkIfParamVersion(args)) {
            try {
                if (LONG_VERSION.equals(args[0])) {
                    System.out.println("The application info is: \n" + readVersionFromClasspath("application.properties", false));
                } else if (SHORT_VERSION.equals(args[0])) {
                    System.out.println(readVersionFromClasspath("application.properties", true));
                }
            } catch (IOException ex) {
                System.out.println("The application.properties file not found version is undefined");
            }
            return true;
        }
        return false;
    }

    private boolean checkIfParamVersion(String[] args) {
        return args.length == 1 && (LONG_VERSION.equals(args[0]) || SHORT_VERSION.equals(args[0]));
    }

    private String readVersionFromClasspath(String fileName, boolean onlyVersion) throws IOException {
        StringBuilder sb = new StringBuilder();
        BufferedReader br;
        br = new BufferedReader(new InputStreamReader(new ClassPathResource(fileName).getInputStream(), "UTF-8"));
        String line;
        while ((line = br.readLine()) != null) {
            if (onlyVersion) {
                if (line.startsWith("info.app.version=")) {
                    line = line.replaceAll("info.app.version=", "");
                    return line;
                }
            } else {
                sb.append(line).append("\n");
            }
        }
        return sb.toString();
    }

    public static VersionedApplication versionedApplication() {
        return new VersionedApplication();
    }
}